The FDA approves a blood test to aid assessment after head injury. The Food and Drug Administration (FDA) has approved a blood test for two protein biomarkers (UCH-L1 and GFAP) that may help providers assess whether computed tomography (CT) is needed after a suspected head injury. The blood test must be performed within 12 hours of the head injury, and results can be available within three to four hours. The test was developed to provide objective data that could help avoid unnecessary CT scanning, according to the manufacturer. The FDA views it as an aid in the neurological evaluation process and facilitated the test's approval as part of the agency's Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging, said Commissioner Scott Gottlieb.